Designing Green Roofs with Native Plants, A French Living Roof

Native wildflowers and plants offer much more than cleaning stormwater and providing habitat.

Most importantly, their inherent beauty creates a 'Sense of Place' we all long for.  This 'Sense of Place' desire is an emotion that is embedded deeply within our DNA and as a population it has only been but a small fraction of time that we've lived apart from nature in the Urban Core.  Wildflowers and Homo sapiens have had a close relationship since the dawn of time.

Moreover, in addition to the intrinsic beauty a planting of native wildflowers adds to a rooftop, the plants also create habitat for wildlife, clean stormwater, sequester carbon, pump out fresh oxygen for us to breath, help cool the cities and more!

In conversation with one of the pioneers of French Living Roofs using native plant species I was fortunate to obtain a proposed and draft species list for an extensive (approximately 100 - 120 mm thick) vegetated roof for biodiversity.

The designer, Pescalune (you can follow on Twitter http://twitter.com/toitsverts ) in conjunction with Dusty Gedge from Living Roofs are designing an extensive living roof system that takes advantage of local native materials.  Dusty can be followed on Twitter at http://twitter.com/greenroofsuk

Being privy to the potential native plant list, I could not help but quickly draw a sketch of what the natives may look like en masse when blooming.  Granted the plants will not bloom all at the same time however many flowers will be open concurrently. Not to scale, but you get the general idea of beauty.

Green Roof France, Toits Verts Pour Le Pescalune

The plant species list under consideration is interesting because many of those cultivated species here in the States are found growing naturally in France.

Potential Green Roof France natives include:

·    Aster tripolium L. Sea Aster

·    Borago officinalis Borage

·    Calendula officinalis Pot marigold

·    Crocus, Wild Crocus

·    Dittrichia viscosa, False Yellowhead

·    Erysimum cheiri (syn. Cheiranthus cheiri) Aegean wallflower

·    Fumaria officinalis Common Fumitory or Earth smoke

·    Lamium Deadnettle

·    Limonium vulgare, Common sea-lavender

·    Ornithogalum umbellatum, Star of Bethlehem

·    Papaver rhoeas, Corn Poppy

·    Phacelia tanacetifolia  Lacy phacelia.

·    Plantago lanceolata Ribwort plantain

·    Portulaca oleracea Common Purslane

·    Scabiosa, Scabious

·    Spergularia marina, Lesser Sea-Spurrey

·    Taraxacum officinale, Common Dandelion

·    Trifolium pratense L., Red Clover

·    Urtica, Nettle

·    Veronica chamaedrys L. Germander Speedwell, Bird's-eye Speedwell,

·    Viola

Others under consideration are:

• Chamaemelum nobile, Roman Camomille
• Melissa officinalis Lemon balm 
• Satureja
• Origanum majorana Marjoram
• Eruca sativa , Rocket

I love the way the Arugula is called 'Rocket'!  

If you caught yesterday's post of the rooftop arugula you'd see why green roofs are so important for biodiversity (great bee photo here).

Considering a living roof?  You might just want to consider using wildflowers and native species endemic to your site.

As always, feel free to email us with comments and questions.

Happy Green Roofing!

Kevin